1. Field
The following description relates to an apparatus and a method for efficiently processing multiple continuous aggregate queries in data streams.
2. Description of the Related Art
The consumption of high speed, unbroken data streams has grown. A technology that processes a data stream is utilized in various ways, including in production and maintenance management, network management systems, stock trading systems, traffic information systems, cloud computing and health care. On top of this, widely-used IP systems and ubiquitous computing environments have further caused an explosion in data usage. Hence, a technology that processes a data stream more efficiently is needed.
While a commonly-used technology that processes data stores the data before processing, a technology that processes a data stream processes the data stream before storage, and thus, requires a new processing technique. In addition, the technology that processes a data stream should use as little memory as possible to provide a quick response during processing of the data stream.
Generally, a concept of a pane is used to process continuous aggregate queries in a data stream. A technique using the concept of the pane includes dividing a window of time by a size of the greatest common divisor between a range and a slice, generating aggregate operation results based on the divided window and sharing the aggregate operation results. This technique yields decent performance in the case of a single overlapping window, but fails to efficiently deal with a plurality of overlapping windows and is not particularly useful in sharing aggregate operation results since the size of a pane is close to 1.